Yangtse River dolphin declared extinct

18/01/2008 00:00:00

A team of scientists have concluded that the Yangtze River dolphin, or baiji, is now extinct following comprehensive surveys of its habitat. This represents the first extinction of a large vertebrate for more than fifty years and the only species of cetacean (whale, dolphin or porpoise) ever to have been driven to extinction by human activity.

Dr Turvey, of the Zoological Society of London, commented, ‘The loss of such a unique and charismatic species is a shocking tragedy. The Yangtze River dolphin was a remarkable mammal that separated from all other species over twenty million years ago. This extinction represents the disappearance of a complete branch of the evolutionary tree of life and emphasises that we have yet to take full responsibility in our role as guardians of the planet.’<>p

An intensive six week survey was undertaken at the end of 2006, which covered the entire historical range of the species in the main channel of the Yangtze River in eastern China. If any dolphins were found it was planned that they would be translocated to a nearby oxbow lake where a captive breeding programme would be undertaken. Unfortunately, not a single individual was found and the expert international scientists involved in the project have been forced to concede that the species has become extinct. It is believed that the main factor responsible for the disappearance of the baiji was the accidental death of large numbers of dolphins in fishing gear, rather than active persecution.

Baiji not quite extinct yet.

30th August 2007. Just a few days after the Baiji, or Yangtse River dolphin, was declared extinct, one has apparently been filmed! Although the pictures are not very clear, experts are fairly confident that the film did indeed show a Baiji swimming near Tongling city, a stretch of the Yangtse where they used to be relatively common. However assuming it was a baiji, the chance of there being enough surviving to maintain a population is miniscule, so they are functionally, if not factually extinct.

At the start of 2007, ZSL launched its EDGE programme, a conservation programme focused on the world’s most Evolutionarily Distinct and Globally Endangered species. EDGE has assessed all of the world’s mammals in terms of how closely or distantly related each species was to its nearest relatives, and how endangered it was. The programme calculated the Yangtze River dolphin to be the Number 1 EDGE mammal.

Dr Turvey added, ‘The baiji’s extinction also highlights the need for new conservation initiatives in China’s increasingly threatened Yangtze ecosystem, which is also home to endangered freshwater porpoises, seven-metre long fish, giant salamanders and white Siberian cranes.’

The paper, lead-authored by Dr Sam Turvey of the Zoological Society of London (ZSL), is published in the Royal Society’s journal Biology Letters.